7
$\begingroup$

The OTRAG rocket is an interesting design. Vehicles would be assembled from 4 to hundreds of identical rocket modules. By using an extremely simple design, producing the modules cheaply using economies of scale, and not bothering with recovery and refurbishing, it was expected to be 1/10 the cost of similar vehicles. (Basically, the exact opposite of the shuttle's philosophy.)

The Wikipedia article is a fascinating read of what can be done with a simple, clever design.

It appears that the program failed entirely due to geopolitical reasons. OTRAG was a German company, and France and the Soviet Union did not want Germany to have another rocket program. The launches occurred in Congo and Libya, both run by dictators. The owner of OTRAG did not want to give 50% control to Americans, which would be legally required for U.S. assistance. Nonetheless, there were 18 test flights of the concept. The linked page claims that it was human-rated (if that can be believed).

Have there been any other launch vehicle designs like the OTRAG? Specifically, the vehicle should be (1) built of modular units and (2) non-reusable. So for example, the Ares family would qualify for the former but not the latter.

$\endgroup$
  • $\begingroup$ The ratio of structural weight to fuel weight is bad for 4 modules and gets worse for an increasing number of modules. Reliabilty of a vehicle consisting of hundreds of modules may be bad. Failure of some percent of modules should be tolerated. $\endgroup$ – Uwe Sep 3 '18 at 9:51
3
$\begingroup$

The Conestoga launcher is the only similar design I know of, in that it involved clustering large numbers of identical boosters. The bigger the payload, the more boosters. Unlike OTRAG the boosters were solids.

There were two flights, the last one was a failure. Although not orbital, the first one reached space. The 2nd one used the clustered configuration, the first flight didn't. The 2nd flight was an attempt to orbit a payload.

enter image description here

(image source)

$\endgroup$
  • 1
    $\begingroup$ That's a pretty kerbal looking rocket, and a pretty kerbal design philosophy - need to lift more? MORE BOOSTERS! $\endgroup$ – Baldrickk Sep 5 '18 at 15:22
3
$\begingroup$

As far as I know Besides the solid-rocket Conestoga, there have been no launcher designs even remotely similar to OTRAG that got anywhere near full-scale testing.

Falcon 9/Heavy, Delta IV/Heavy, their corresponding "superheavy" (4-6 booster) concepts, and the Angara family (0, 2, 4, or 6 boosters) are all based on using similar core-and-booster stages, but the commonality ends with the first stage; OTRAG instead starts with the uppermost stage (or rather, a fraction of uppermost stage) as the unit of commonality.

$\endgroup$
3
$\begingroup$

Soviet UR-700 and UR-900 were the projects of modular superheavy rockets, but never implemented. Only single-core Proton launcher became operational.

Wiki page about UR series

UR-700

UR-900

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.